NCEI added Alaska climate divisions to its nClimDiv dataset on Friday, March 6, 2015, coincident with the release of the February 2015 monthly monitoring report. For more information on this data, please visit the Alaska Climate Divisions FAQ.

U.S. Percentage Areas

More Information

National Overview:

Major climate events NOAA is closely monitoring:

Persisting and intensifying drought in parts of the West and the Central and Southern Plains: Long- and short-term dryness will continue to increase wildfire risk and impact water resources and agriculture. More information is available from the U.S. Drought Monitor.

Probability of El Niño increases later this year: According to NOAA's Climate Prediction Center, there is a 70 percent chance of El Niño conditions developing this summer, increasing to an 80 percent chance by autumn and winter. El Niño conditions could have significant impacts on temperature and precipitation patterns across the United States. More information is available from the Climate Prediction Center.

The North Atlantic hurricane season began on June 1: According to NOAA's Climate Prediction Center, the 2014 North Atlantic hurricane season is forecasted to be near-normal or below-normal in terms of the number of tropical storms, hurricanes, and major hurricanes. The last North Atlantic hurricane season with a below-average number of named storms was in 2009. More information is available from the Climate Prediction Center and NOAA's National Hurricane Center.

A large portion of the central U.S. had temperatures near the 20th century average, while above-average temperatures were observed along the West Coast and the East Coast. California tied its ninth warmest May on record, with a statewide temperature 3.9°F above average. This marked the seventh consecutive month with above-average temperatures for California. No other state had May temperatures that ranked among the 10 warmest or coldest on record.

The May national precipitation total of 2.76 inches was 0.15 inch below the 20th century average, ranking near the middle of all Mays in the 120-year period of record.

Below-average and above-average precipitation totals were scattered across the country. Above-average precipitation was observed across the Northeast and in Texas, where it provided minor and short-term drought relief. Below-average precipitation was observed in the Southwest, Northern Rockies, Central Plains, and parts of the Midwest. Kansas had its sixth driest May on record, with 2.02 inches of precipitation, 1.83 inches below average.

According to the June 3 U.S. Drought Monitor report, 37.3 percent of the contiguous U.S. was in drought, down about 1.1 percent compared to the end of April. Both improvement and degradation of drought conditions occurred on the regional scale. Beneficial rain improved drought conditions across parts of Texas, Nebraska, and Iowa. In Texas, despite the short-term precipitation relief, extreme and exceptional drought coverage in the state is five times greater than at the start of the calendar year. Drought conditions worsened in parts of Kansas and Oklahoma. The long- and short-term dry conditions across the Southern Plains and the West helped fuel several large wildfires that threatened homes during May.

May precipitation totals were mixed across Hawaii. Locations on the Big Island were drier than average, which caused an expansion of abnormally dry conditions, according to the U.S. Drought Monitor. Locations on Oahu, Kona, and Maui had their wettest May on record, while the Honolulu airport had its wettest May since 1978.

During May, there were slightly more record warm daily highs and lows (3275) as record cold daily highs and lows (2937).

Based on NOAA's Residential Energy Demand Temperature Index (REDTI), the contiguous U.S. temperature-related energy demand during May was 74 percent below average and the 11th lowest in the 1895-2014 period of record. The above-average temperatures across the densely populated Northeast region contributed to the below average REDTI during May.

Climate Highlights — spring (March – May)

The average temperature for the contiguous U.S. during spring was 51.1°F, 0.2°F above the 20th century average, ranking near the middle among all springs in the 120-year period of record.

Above-average spring temperatures were observed from the Rockies, westward. The California statewide average temperature tied with 2013 as the fifth warmest spring on record with a seasonal temperature 4.1°F above the 20th century average. Each season since the winter of 2012/13 has been warmer than average in California.

Below-average temperatures were interspersed with near-average temperatures across the eastern two-thirds of the Lower 48. No state had spring temperatures that ranked among the 10 coldest, although Louisiana and Wisconsin both had their 11th coldest spring on record, with temperatures 2.1°F and 3.2°F below average, respectively.

Below-average precipitation was observed from the Southern Rockies into parts of the Midwest, with the driest conditions across the Central and Southern Plains. Kansas had its third driest spring on record and driest since 1966, with 4.08 inches of precipitation, barely half the average. Oklahoma had its ninth driest spring and driest since 2005, with 6.42 inches of precipitation, 4.31 inches below average.

Above-average precipitation fell across the Pacific Northwest, the Upper Midwest, and along much of the East Coast and Gulf Coast. Washington state had its fourth wettest spring with 13.88 inches of precipitation, 4.65 inches above the 20th century average.

Alaska had its eighth warmest spring on record, with a seasonal temperature 3.1°F above the 1971-2000 average. The spring heat in Alaska peaked in May, which was the state's sixth warmest in the 1918-2014 record. Many locations across the state, including Anchorage, King Salmon, and Kodiak, had their warmest May on record. Alaska also had its 25th driest spring on record, with a precipitation total 14.7 percent below the 1971-2000 average. The combination of a warm and dry spring contributed to the state having its smallest May snow cover extent in the 48-year period of record.

The U.S. Climate Extremes Index (USCEI) for spring was near average. On the national-scale, the spatial extent of one-day precipitation extremes ranked as the third highest spring value on record at 60 percent above average. On the regional scale, the elements that track the spatial extent of cold daily highs and lows were elevated across the central U.S., one-day precipitation extremes were record and near-record high in the East, while the spatial extent of drought was record high in the West. The USCEI is an index that tracks extremes (falling in the upper or lower 10 percent of the record) in temperature, precipitation and drought across the contiguous U.S.

Based on REDTI, the contiguous U.S. temperature-related energy demand during spring was 6 percent above average and the 56th highest in the 1895-2014 period of record.

Climate Highlights — year-to-date (January – May)

The year-to-date average temperature for the contiguous U.S. was 43.2°F, 0.1°F below the 20th century average, ranking near the middle value in the 120-year period of record. This was the coldest first five months of any year since 1996.

During the first five months of 2014, above-average temperatures were widespread in the West. Five states had one of their 10 warmest starts to the year. California's January-May temperature of 55.2°F was 5.0°F above the 20th century average, marking the warmest such period for the state. This bested the previous record, set in 1934, by 0.1°F.

Below-average January-May temperatures were widespread east of the Rockies. Thirteen states, from the Upper Midwest to the Gulf Coast, had year-to-date temperatures that ranked among the 10 coldest on record. The largest departures from average occurred across the Great Lakes region. No state had five-month temperatures that were record cold.

The national precipitation total for the first five months of 2014 was 11.62 inches, 0.77 inch below the 20th century average, tying with 1941 as the 34th driest January-May on record.

During the January-May period, below-average precipitation was observed in the Southwest and much of the Great Plains. Arizona had its fourth driest start to the year, while Kansas had its second driest and Oklahoma its third driest. Above-average precipitation was observed across the northern tier of the country and the Southeast. Florida had its eighth wettest start to the year.

The USCEI for the year-to-date was the 14th highest value on record, at 145 percent of average. Elements that contributed to the above-average USCEI included: the spatial extent of cold maximum and minimum temperatures, warm maximum temperatures, one-day precipitation totals and the spatial extent of drought.

Based on REDTI, the contiguous U.S. temperature-related energy demand during January-May was 21 percent below average and the 29th highest in the 1895-2014 period of record.

**A comparison of the national temperature departure from average as calculated by NCDC's operational dataset (nClimDiv), the U.S. Historical Climatology Network (USHCN), and the U.S. Climate Reference Network (USCRN) is available on our National Temperature Index page.**

Alaska Temperature and Precipitation:

Temperature

Alaska had its 6th warmest May since records began in 1918, with a temperature 3.56°F (1.98°C) above the 1971-2000 average.

Alaska had its 8th warmest March-May since records began in 1918, with a temperature 3.13°F (1.74°C) above the 1971-2000 average.

Alaska had its 2nd warmest January-May since records began in 1918, with a temperature 5.33°F (2.96°C) above the 1971-2000 average.

Precipitation

Alaska had its 20th wettest May since records began in 1918, with an anomaly that was 17.86% above the 1971-2000 average.

Alaska had its 25th driest March-May since records began in 1918, with an anomaly that was -14.75% below the 1971-2000 average.

Alaska had its 27th driest January-May since records began in 1918, with an anomaly that was -5.55% below the 1971-2000 average.

For additional details about recent temperatures and precipitation across the U.S., see the Regional Highlights section below and visit the Climate Summary page. For information on local temperature and precipitation records during the month, please visit NCDC's Records page.

For the first time since October 2013, the monthly average temperature for the Northeast was warmer than normal. The region's average temperature was 57.5 degrees F (14.2 degrees C), 1.2 degrees F (0.7 degrees C) above normal. All states were warmer than normal, as well. Delaware had the largest departure, +2.4 degrees F (+1.3 degrees C), making it the state's 15th warmest May on record. Departures for the rest of the states ranged from +1.8 degrees F (+1.0 degree C) in Maryland to +0.3 degrees F (+0.2 degrees C) in Maine.

The Northeast wrapped up May with above-normal precipitation, receiving 4.50 inches (114.3 mm) or 111 percent of normal. Eight of the twelve states were wetter than normal. Maryland picked up 132 percent of normal, making it the state's 18th wettest May on record. Departures for the other wet states ranged from 125 percent of normal in Pennsylvania to 105 percent of normal in Connecticut. For the dry states, departures ranged from 91 percent of normal in Delaware and Massachusetts down to 83 percent of normal in Rhode Island.

According to the U.S. Drought Monitor released May 1, parts of northeastern West Virginia, western Maryland, and southern Pennsylvania (2 percent of the Northeast) were abnormally dry. The following week, dry conditions expanded in West Virginia and Pennsylvania to cover 9 percent of the region. However, by mid-month precipitation had eased dryness in all but southern West Virginia (1 percent of the region).

From mid to late May, multiple rounds of severe weather hit the region. Extreme rainfall, in some cases a month's worth or more in a few hours, caused flash flooding that significantly damaged buildings and shut down roads. Four tornadoes (ranging in strength from EF-0 to EF-3), straight-line winds, and pea to baseball sized hail also caused extensive damage. According to the USDA Crop Report from May 6, only 5% of potatoes had been planted in New York compared to the 5-year average of 42% and in Pennsylvania only 34% of apple trees were in full bloom versus the 5-year average of 91%. By mid-May, the strawberry crop had been delayed 1-3 weeks across the region, causing a shortened berry-picking season. While improving conditions in late May allowed many farmers to make significant progress in their fields, some crops remained behind schedule.

May temperatures were slightly above normal in the southern half of the Midwest and near to slightly below normal in the northern half of the region. The region wide temperature in May was above normal for the first month in 2014. The string of cooler than normal months began in November 2013. Individual statewide temperatures remained below normal in the northern states with Iowa extending to eight straight months and Minnesota, Wisconsin, and Michigan extending to seven straight months below normal. The region wide temperature for January to May 2014 ranked in a tie for the seventh coolest in the past 120 years. Statewide values for the same period ranked among the ten coolest for all Midwest states except Kentucky. Spring temperatures were below normal across the Midwest with Kentucky the closest to normal and the northern states falling the most below normal.

May precipitation was below normal for much of the Midwest. The driest areas were pockets of less than half of normal precipitation in northern Missouri, west central Illinois, southeast Iowa, and northwest Iowa. Wet areas for the month were mostly in the northern states with some areas receiving more than 150 percent of normal. Spring precipitation was slightly wetter than the pattern for May with the northern states mostly above normal along with a swath from southeast Missouri to northeast Ohio. Drier spring conditions were most pronounced in northwest Iowa where totals were less than half of normal. Other areas with less than 75 percent of normal extended into Minnesota, Missouri, and Illinois.

Drought conditions in May showed slight improvements in both coverage and intensity. Despite the improvements overall, western Missouri saw some degradation. Areas in the western half of the region and in southeast Kentucky were being watched closely for drought impacts.

Severe weather in the Midwest picked up after a relatively quiet April. Several days had widespread severe weather including the 21st when large hail pounded a town in east central Illinois. A hail storm lasting about 20 minutes struck in Tuscola, Illinois with hail up to 4 inches (10 cm) in diameter. Roofs, siding, windows, and cars were totaled as the hail dented and tore through buildings and vehicles as the storm slowly moved right through the middle of the community. There were no injuries reported, possibly due to a few minutes of smaller hail at the beginning of the storm which gave people time to seek shelter prior to the larger hail falling.

Planting of corn and soybeans was behind normal as the month began but favorable field conditions allowed farmers to catch up to normal during the month. Much of the corn crop was planted by the end of the month, slightly ahead of normal. Soybean planting was ahead of normal in the south but remained behind normal in the north.

Mean temperatures in May were above average across the Southeast region. The greatest departures were found across the Carolinas and Virginia, where monthly temperatures were 2 to 4 degrees F (1.1 to 2.2 degrees C) above average. Charleston, SC recorded its third warmest May in a record extending back to 1938. The warmest weather occurred from the 23rd to the 25th of the month, as temperatures reached the upper 90s F (30s C) across parts of Florida, Georgia, and South Carolina. Charleston, SC recorded a maximum temperature of 97 degrees F (36 degrees C) on the 23rd, which was just 2 degrees F (1.1. degrees C) short of the highest maximum temperature ever recorded in May at that location. Unseasonably warm weather was also observed from the 12th to the 14th of the month, as maximum temperatures reached 90 degrees F (32 degrees C) as far north as the Washington D.C. area. In contrast, the coldest weather occurred from the 16th to the 19th of the month, as temperatures were 10 to 20 degrees C (5.5 to 11.1 degrees C) below average as far south as central Georgia and Alabama. Monthly temperatures were variable across Puerto Rico and below average across the U.S. Virgin Islands. San Juan, PR recorded its third warmest meteorological spring (March-May) in a record extending back to 1898.

Monthly precipitation totals were variable across the Southeast in May. The wettest locations were found across the northern Gulf coast, including the Big Bend region of Florida, where monthly precipitation totals were as much as 300 percent of normal. Heavy thunderstorms on the 14th and 15th of the month also contributed to above-normal rainfall across parts of Georgia, the Carolinas, and Virginia. Many locations received 2 to 3 inches (50.8 to 76.2 mm) of rain, while some locations received up to 8 inches (203.2 mm). Precipitation was also above normal across much of Puerto Rico. Most notably, a tropical wave produced up to 20 inches (508 mm) of rain along the northern shores between the 8th and 11th. Monthly precipitation was also above normal across the U.S. Virgin Islands. In contrast, the driest locations were found across South Florida, southern sections of Puerto Rico, and coastal sections of Virginia and the Carolinas, where monthly totals were less than 50 percent of normal. A trace of snowfall was reported at Mount Mitchell on the 17th of the month, which marked the fourth latest snowfall observation in a calendar year at the summit since records began in 1980. May marked the end of an exceptionally wet spring across parts of the northern Gulf coast. Most notably, Pensacola, FL (1880-2014) recorded its wettest meteorological spring on record, with 45.15 inches (1146.8 mm), breaking the previous record of 39.34 inches (999.2 mm) set in 2005.

Over 300 reports of severe weather were recorded across the Southeast in May, including 13 confirmed tornadoes. Most of these occurred in advance of a strong cold front on the 14th and 15th of the month. The strongest tornadoes were rated EF-1 and were observed in northeast Georgia, northeast Florida, and central North Carolina. The remaining tornadoes were observed in southern Georgia, eastern Alabama, northern Virginia, and near the Miami International Airport in South Florida. No casualties were reported. Severe storms near Columbia, SC produced hailstones between 1 and 3 inches (25.4 and 76.2 mm) in diameter on the evening of the 23rd.

Only minor changes were noted in the Drought Monitor across the Southeast in May. There was a slight expansion of abnormally-dry conditions (D0) across northern portions of Alabama and Georgia, as well as extreme western North Carolina and Virginia. A small region of moderate drought (D1) emerged across extreme southern Florida, where precipitation deficits over the past several months have been the greatest. The Florida Climate Center reported that planting of field crops across the Panhandle was running 2 to 4 weeks behind schedule due to excessive rainfall and flooding. Reports of wet field conditions, disease, and delays in planting and hay cutting were also reported across parts of Georgia.

May 2014 average temperatures in the High Plains Region were near normal, within 2.0 degrees F (1.1 degrees C) above or below normal. These near normal average temperatures hid the extremes that occurred during the month. For instance, Wichita, Kansas went from near record cold of 35 degrees F (1.7 degrees C) on the 2nd to record warmth with 102 degrees F (38.9 degrees C) on the 4th. That turned out to be the earliest 100 degree F (37.8 degree C) day on record and completely smashed the old daily record of 94 degrees F (34.4 degrees C) set back in 1963 (period of record 1888-2014). Wichita was actually one of the few warmer locations in the Region and managed to have its 7th warmest May on record with an average temperature of 70.0 degrees F (21.1 degrees C). These large swings in temperature put even more stress on the already struggling winter wheat crop in Kansas. Although the final assessment on the late freeze event is not yet available, by the end of the month 61 percent of the winter wheat crop in Kansas was in poor to very poor condition according to NASS. There have even been reports that crop insurance payments have already begun to be disbursed, which is quite early. Meanwhile, cooler air and soil temperatures have slowed planting in some northern areas of the Region. This delayed planting and development has some producers concerned for this year's harvest.

The majority of the High Plains Region was dry this month with the driest portions including central Wyoming, eastern Kansas, pockets of the Dakotas, and a swath stretching from eastern Colorado, through much of Kansas, and north into Nebraska. These areas received at most 50 percent of normal precipitation. This lack of precipitation caused some locations to be ranked in the top 10 driest Mays on record. Grand Island, Nebraska had its 5th driest May with 0.74 inches (19 mm) which was 3.67 inches (93 mm) below normal, or 17 percent of normal precipitation (period of record 1896-2014). The driest May on record occurred in 1934 with 0.34 inches (9 mm). Topeka, Kansas also ranked in the top 10 driest Mays on record. With only 1.63 inches (41 mm), or 33 percent of normal, this ranked as the 9th driest May for Topeka. The record of 0.41 inches (10 mm) was set in 1966 (period of record 1887-2014). The main exception to the dryness was a swath of above normal precipitation running from western to northern Colorado into the panhandle of Nebraska ending in central South Dakota. Parts of North Dakota also received above normal precipitation. One example was Dickinson, North Dakota which had its 2nd wettest May on record with 6.18 inches (157 mm). This amount bumped last year's 6.03 inches (153 mm) down to the number 3 spot, but was not enough to beat out the 6.52 inches (166 mm) received in 1962 (period of record 1949-2014). One of the notable storm systems of the month was the Mother's Day storm which brought accumulating snowfall to the west and severe weather to the east. The highest snowfall amounts ranged between 1 and 2 feet (30-61 cm) in the mountains of Colorado and Wyoming. Travel delays were numerous as portions of I-25 and I-70 in Colorado closed and portions of I-80 were closed in Wyoming and Nebraska. Numerous tornadoes, high winds, and large hail were reported in Nebraska, Kansas, South Dakota, and Iowa. According to the Omaha/Valley National Weather Service Office, one supercell produced 12 tornadoes along a 119 mile stretch in eastern Nebraska. Even one of the HPRCC's Automated Weather Data Network (AWDN) stations had a close call with the Beaver Crossing tornado. A 5-second wind gust of 119 mph (192 km/hr) was recorded at the station and damage to trees and center pivots occurred nearby.

Overall, there were only slight changes to the U.S. Drought Monitor in the High Plains Region this month. Although some areas had improvements and others had degradations, the areas experiencing moderate (D1) to exceptional (D4) drought remained at about 33 percent. The most significant changes occurred in Kansas where there was a 20 percent increase in extreme drought conditions (D3). Exceptional drought conditions (D4) were also introduced across the southern border of the state. In Nebraska, D1 and D2 were trimmed in areas receiving ample precipitation, but a new area of D3 emerged in the central part of the state. D1 also expanded northward into southeastern South Dakota. A small area of D3 also expanded to include all of southeastern Colorado. According to the U.S. Seasonal Drought Outlook released May 15th, current drought conditions are expected to persist or intensify across far southeastern Colorado and southern Kansas through August. Meanwhile, drought conditions may improve or be eliminated in other parts of Colorado, Kansas, Nebraska, and South Dakota.

Precipitation totals for the month of May illustrate that for parts of the Southern Region, it was a very wet month, while for other areas, it very much the opposite. In Texas, central and southern counties received between two and three times the normal amount of precipitation. This was also the case for the south central and south eastern Louisiana, and southern Mississippi. In central Arkansas, precipitation totals varied from near normal to approximately one and a half times normal. Elsewhere, precipitation was scarce. The western panhandle of Texas, for instance, averaged between zero and fifty percent of normal, with most stations averaging near one quarter of normal precipitation. This was also the case in central Tennessee, and in east central and northern Oklahoma. The statewide average precipitation totals are as follows: Arkansas averaged 5.87 inches (149.10 mm), Louisiana averaged 7.33 inches (186.18mm), Mississippi average 5.13 inches (130.30mm), Oklahoma averaged 2.99 inches (75.95mm), Tennessee average 2.89 inches (73.41mm) and Texas averaged 4.03 inches (102.36mm). For Louisiana it was the seventeenth wettest May on record (1895-2014), while for Texas, it was their thirtieth wettest May (1895-2014). Conversely, Oklahoma experienced its twenty-eighth driest May on record (1895-2014), while for Tennessee, it was their twenty-first driest May (1895-2014). All other state rankings fell within the two middle quartiles.

Drought conditions in the Southern Region did not significantly change in the states of Arkansas, Mississippi, Louisiana, or Tennessee, with all four states remaining relatively drought free. Heavy rains in Texas and north western Oklahoma have led to a dramatic reduction in areal coverage of exceptional drought over the past month. There was also a significant reduction in the amount of severe and extreme drought in central Texas. Despite these improvements, approximately one fifth of the Southern Region (mostly Oklahoma and northern Texas) is still experiencing extreme to exceptional drought. Almost half the region (46.47 percent) is currently experiencing some form of drought.

Baseball-sized hail was reported in Texas on the twelfth of the month in Tarrant County, and on the twenty-fourth in both Terrell County and in Pecos County.

In Texas, winter wheat production is estimated to be down from 2013. The USDA estimated that though the 29 bushels per acre is unchanged from last year, only 55.1 million acres, down from 65.3 million acres, are expected to be harvested; the Blacklands were the worst off, dropping 36 percent in their estimated acres harvested. Other Texas grains harvests are expected at 1.9 million acres, down 16 percent from this time last year. By the end of the month, only 62% of cotton acreage had been planted, down from 74% last year and the 75% 5-year average. The recent rains have greatly helped the corn crop, with less than 10% poor to very poor and almost 50% being good to excellent, up from around 20% at the beginning of the month (Information Provided by the Texas Office of State Climatology).

The drought in Texas, continues to have heavy impacts. Wichita Falls, despite the recent rains, officially began Stage 5, Drought Catastrophe water restrictions this month. Several small communities across the state are in danger of running out of drinking water within 45-90 days, leading small loans to be given out by the Texas Department of Agriculture, such as the $350,000 well loan for Pebble Beach in Bandera County. As planning for the future of Texas's water supply continues, debate on the true number for future water use falls under scrutiny, as new reports argue that less than half of 2.7 trillion estimated gallons of water would be needed; this would encompass all of the controversial $3.3 billion reservoir proposed for the Dallas-Fort Worth metropolitan area (Information Provided by the Texas Office of State Climatology).

Unsettled spring weather continued this month with periods of high pressure and above normal temperatures interrupted by the passage of several weak low-pressure systems. Temperatures were generally near normal throughout the West, with a gradient from slightly above normal along the coast to slightly below normal in the Rocky Mountain states. Scattered areas of above normal precipitation dotted the West this month, though a majority of the region saw drier than normal conditions.

Following several months of above normal precipitation, most of the Inland Northwest saw less than 75% of normal in May. Idaho Falls received only 0.17 in (4 mm) of precipitation, 11% of normal, and the fourth driest May in a 67-year record. Dry conditions continued for much of California, especially the coastal regions. Much of the San Francisco Bay Area received less than 0.1 in (3 mm) for the month. San Jose recorded no measurable rainfall in May, tie for driest with 21 other years in its 122-year record. Further south, Paso Robles and Los Angeles also received no measurable precipitation. May is typically the tail end of the precipitation season here and brings little relief from drought. In 121 years at Paso Robles and 138years at Los Angeles, 32 and 39 other years, respectively, saw no measurable May precipitation. Also in the Southwest, Arizona experienced typically dry conditions. Tucson averages 0.23 in (6 mm) of rainfall in May but received none this month; however, the same is true for 41% of Mays in the station's 120-year record. Snowpack continued to dwindle in the Sierra Nevada and Great Basin, while holding near to above normal in the northern Cascades and northern and central Rockies. Below average streamflow is expected throughout the Great Basin, while copious runoff is anticipated on both sides of the Continental Divide in early summer.

A slow-moving low-pressure system towards the end of the month brought beneficial precipitation to the drought-stricken western Great Basin as well as portions of the Four Corners states. Reno, Nevada saw above normal monthly precipitation for the first time since August 2013 with a total of 0.54 in (14 mm), 110% of normal. Bishop, California received 0.24 in (6 mm) of precipitation, 126% of normal. This low helped to drive moisture from the Gulf of Mexico northward into New Mexico, resulting in heavy precipitation in the eastern portion of that state on the 23rd and 24th. Roswell received 4.44 in (112+ mm) on the 24th, making for the wettest single day in the past 69 years. Roswell received 4.45 in (113 mm) for the month, 281% of normal and the 2nd wettest May on record. Moab, in eastern Utah had its wettest May in a 121-year record at 2.65 in (67 mm). In the Pacific Northwest, areas within and west of the Cascades saw abundant precipitation this month as well. Seattle recorded 3.15 in (80 mm) for the May, the 8th wettest since records began in 1948.

Warmer than normal temperatures dominated coastal areas of the West this month. In Southern California, Santa Maria experienced its warmest May in a 67-year record at an average 64.0 F (17.8 C), 6 F (3.3 C) above normal. This included a recording of 105 F (40.5 C) on the 15th, the highest May temperature and the second highest all-time temperature observed in Santa Maria. Further up the coast, temperatures at North Bend, Oregon, averaged to 56.8 F (13.8 C) for May, 3.9 F (2.2 C) above normal and the fourth warmest since records began in 1902. Elsewhere in the West, average May temperatures were 1-4 F (1-2 C) cooler than normal in the Four Corners region and northern Montana.

Precipitation was variable across Alaska this month. Above average precipitation was observed along the North Slope, where Barrow recorded 0.9 in (23 mm), the wettest May in a 113-year record. Temperatures were warmer than normal for much of the state, especially in the northern and southern coastal areas. The average temperature at Anchorage this month was 52.1 F (11.2 C), 4.3 F (2.4 C) above normal and the warmest May since records began in 1952. Further south, precipitation was near to above normal throughout Hawaii. On Oahu, Honolulu received 3.35 in (85 mm) of rainfall, the 6th wettest May in a 65-year record. Molokai Airport had its 3rd wettest May since records began in 1949 with 4.51 in (115 mm), 406% of normal.

May 26: Large landslide near Collbran, Colorado: Following two days of heavy rain, a landslide one-half mile (0.8 km) wide and three miles (4.8 km) long occurred in a remote area of western Colorado. Three people were killed in the slide.

May 20 and on: Slide Fire, north of Sedona, Arizona: This fire burned over 21,000 acres (8498 hectares) and was 90% contained at the end of the month. The cause of the Slide Fire is still under investigation. The fire reduced air quality in surrounding areas as well as prompted the evacuation of hundreds of people and many road closures.

May 19 and on: Funny River Fire, Kenai Peninsula, Alaska: This human-caused fire burned over 193,000 acres (78,104 hectares). At month's end, fire containment was at 58% with over 700 firefighters were working on the fire. No homes were lost and no casualties occurred, but many people had to evacuate, some recreational areas were closed, and burn bans were in effect for two weeks.

May 13-17: San Diego County Wildfires: At least 10 wildfires broke out between May 13 and 15, burning more than 20,000 acres (8093 hectares). The fires destroyed over 20 homes and businesses and tens of thousands were evacuated from their homes. The blazes were fanned by strong Santa Ana winds.

Citing This Report

NOAA National Centers for Environmental Information, State of the Climate: National Overview for May 2014, published online June 2014, retrieved on August 2, 2015 from http://www.ncdc.noaa.gov/sotc/national/201405.